How to delete old songs off your ipod touch or iphone?

I got my first ipod touch at 16 (i worked for it myself). Today i bought my iphone and am downloading my music and didn't want to dowload a few songs, but on accident i hit download all. I was wondering how to delete these songs after or how to get rid of my unwanted music with out losing it all?

If you have ios6 you can swipe to the left on the song you don't want and just hit delete